Former NCAA singles champions Mackenzie McDonald and Marcos Giron won their matches on Wednesday at the San Diego Open ATP 250.
McDonald beat error-prone Henri Laaksonen of Switzerland 6-0, 6-2 in just 54 minutes.
Third-seeded Giron moved into the quarterfinals with a 6-4, 6-3 victory over Argentine Tomas Martin Etcheverry. The world No. 58 converted four of six break-point opportunities and finished with 30 winners to 17 unforced errors.
McDonald, who swept the NCAA singles and doubles titles at UCLA in 2016, earned a rematch in the second round against Jenson Brooksby.
“I’m happy with how I’m playing. I love being in California,” McDonald said. “Henri’s a great player. I just think I took it to him today, played my game.”
Giron advances to face Australia’s James Duckworth.
“I’m pumped to get through this one,” Giron said. “This is my first time being seeded, so it’s interesting coming into a tournament not having played a first-round match. But I’ve been playing well the last month. Tomas is top 100 in the world for a reason.
“Playing in Southern California, it really is home to me,” he added. “It’s amazing to play here.”
Alejandro Tabilo of Chile won 7-5, 6-2 over American Steve Johnson. Colombia’s Daniel Elahi Galan defeated Marc-Andrea Huesler of Switzerland 6-3, 7-5.
In doubles, the wild-card pairing of 2010 NCAA singles winner Bradley Klahn (Stanford) and Spaniard Fernando Verdasco dispatched Hans Hach Verdugo and Treat Huey, 6-4, 6-3.